The present invention relates to a method for producing a Group III-V compound semiconductor used for light-emitting devices, electronic devices and the like and also relates to a semiconductor laser device for emitting laser light at a short wavelength by using the same.
In recent years, semiconductor light-emitting devices (semiconductor laser devices, in particular) for emitting light in a short-wavelength region ranging from the spectrum of ultraviolet to the spectrum of blue have been vigorously researched and developed. This is because such devices ensure an increase in recording density of an optical disk or resolution of a laser printer and are applicable to various types of optical measuring instruments, medical devices, display devices and illuminators.
Examples of materials that can emit light at such a short-wavelength region include Group III-V compound semiconductors containing nitrogen. According to Applied Physics Letters, Vol. 70 (1997) pp. 1417-1419, a semiconductor laser device, including an Si-doped InGaN multi-quantum well active layer, can continuously oscillate at a wavelength of around 406 nm and at room temperature. As described in this document, the operating life thereof is 27 hours on the conditions that the temperature is 20.degree. C. and the output power is 1.5 mW.
However, the operating life of the conventional semiconductor laser device using the InGaN-based compound semiconductors is still far from satisfactorily long, because in practice, an operating life exceeding 10,000 hours is often required.